The purpose of the project is to study the biochemistry, morphology, pharmacology and physiology of synaptic transmission and neuronal connections of nerve cells of the mammalian cochlear nucleus. New results from the following studies give increasing support for a neurotransmitter role for glutamate and aspartate in the cochlear nucleus: 1. Corresponding to terminals of the auditory nerve, rings of aspartate aminotransferase-like immunoreactivity have been found around cells in the ventral cochlear nuclei. 2. The effects of iontophoretically-applied antagonists on auditory nerve and amino acid evoked excitation of anteroventral cochlear nucleus neurons. 3. Glutaminase and aspartate aminotransferase decrease in the cochlear nucleus after lesion of the auditory nerve. Furthermore, 4. the first characterization of proteins in the auditory nerve through a study of axonal transport has been published; the study is being continued. 5. Structural and developmental studies of cochlear nucleus of normal mouse has been carried out. 6. The cochlear nucleus of mutant Reeler mouse has been studied. 7. Studies on connections of the cochlear nucleus, superior olivary region and inferior colliculus have been published.